This is covered in AGK's documentation:
In AppGameKit the integer variable is a signed 32bit value from (-2^31 to 2^31-1)
Quote: "INTEGER Range : -2,147,483,648 to 2,147,483,647"
https://www.appgamekit.com/documentation/principles/1_datatypes.htm
An integer in computer science is most commonly 32 bits too. INT shouldnt really be used to specifically described 64bit numbers
https://en.wikipedia.org/wiki/Integer_(computer_science)
A 64 bit value is normally long long, long word, quadword, quad, etc... If an integer type is used to store 64bits it is normally called an int64 specifically as it is larger than the 'normal' implementation.